Lyme disease is one of the most insidious illnesses around. It gets you while you’re doing something pleasant – like walking in the woods on a summer day.
The tick that carries it is so tiny – the size of the period at the end of this sentence – that you can barely see it. And seeing it is important, because if you pick it off with tweezers within 24 to 48 hours, chances are you won’t get sick.
Finally, the circular red rash that develops around the tick bite is easy to miss. Yet if you ignore it, or the fever, chills, headache and fatigue that will follow in the next few weeks, you may miss your best chance to stop the disease before it turns chronic – and causes trouble for years.
Like chronic fatigue syndrome or fibromyalgia, Lyme disease, especially the chronic form, has been so misunderstood that frustrated patients and mystified doctors have long been at odds. But following a conference of doctors and activists last month at the National Institutes of Health, the hostilities seem to be simmering down and the scientific controversies coming into sharper focus.
Both activists and researchers agree that preventing Lyme disease is both possible and critical. They also agree that no one really knows how many people have it – it’s both vastly underdiagnosed and, in some cases, wrongly diagnosed in people who don’t really have it.
The federal Centers for Disease Control and Prevention in Atlanta counted 16,197 new cases nationwide last year, up from roughly 12,000 the year before. In Massachusetts, there were 361 new cases last year, up from the roughly 150 to 250 a year in recent years. No particular “hot spots” are expected this year, but the disease is spreading slowly throughout the state. “Only a fraction of the true cases are identified and reported,” says Dr. Bela Matyas, medical director of the epidemiology or disease tracking program at the state Department of Public Health.
And reporting may actually be better in the Northeast than elsewhere. Lyme disease was discovered in Connecticut in the 1970s, and conditions in the New England region are ideal for the Lyme disease spirochete, the bacterium that lives in ticks.
The tick that spreads Lyme disease – and two other diseases called babesiosis and ehrlichiosis – has a complex life cycle. In the larval, stage, the tick lives on white-footed mice. The tick then molts, becomes a nymph, drops off the mouse and sits in low brush waiting for another animal to feed on.
It is at this stage that a tick bite is most infectious to humans. In its adult stage, the ticks live on deer. This means that large deer populations – like those on Nantucket, where residents and state officials last week held a hearing to consider culling herds – help keep the ticks’ life cycle humming. Adult ticks can also infect humans, but less readily.
It’s the diagnosis and treatment of Lyme disease that really gets complicated – and controversial.
Once the tell-tale rash is gone, for instance, it is difficult even to diagnose Lyme disease. CDC’s guidelines suggest using a lab test, called ELISA, to check for antibodies against the spirochete. But this test can be inconclusive, so a second more specific antibody test called a Western blot is often done.
But even this may not be decisive. It can take weeks for the body to make antibodies, so a newly infected person may test negative but still have the disease. And some people seem to have Lyme disease without any detectable antibody response.
Some doctors also use another test, called PCR, or polymerase chain reaction, to look for pieces of DNA from the spirochete itself. But if, as some suspect, the spirochete can hide inside nerve and immune cells, this could make it harder to detect by PCR.
For some people who never noticed a bite or rash, the first sign of acute infection is meningitis, an inflammation of the lining of the brain, or a type of facial paralysis called Bell’s palsy, or fainting due to heart block – an electrical malfunction caused when the spirochete infects the the heart.
Once acute Lyme disease is diagnosed, the usual remedy is 10 to 30 days of oral antibiotics – usually doxycycline or amoxicillin, says Dr. Allen Steere, chief of rheumatology and immunology at the New England Medical Center, although a newer drug called Ceftin can also work. (Doxycycline and other drugs in the tetracycline family also fight ehrlichiosis, but it takes a more complex antibiotic regimen to treat babesiosis.)
Even though antibiotics work most of the time, Karen Vanderhoof-Forschner, founder of the Connecticut-based Lyme Disease Foundation, worries because data from animal studies suggest that treatment does not always make infection go away.
And if the initial infection is not adequately treated, the bacteria can lurk in the joints and the nervous system, producing chronic Lyme disease – even years later.
In some people, the result is arthritis in the knee, in others, it’s a brain problem called encephalopathy which leads to memory impairment and irritability. Still others develop pain, numbness, and tingling in the hands and feet.
It’s still unclear whether these problems result chiefly from a flareup of a latent infection or, as may happen with arthritis, from an auto-immune attack in which the body attacks tissues harboring the spirochete.
“I think chronic Lyme disease is a persistent infection and that we haven’t figured out how to get rid of enough bacteria to cure people,” says Dr. Sam Donta, an infectious disease specialist at Boston Medical Center and the Boston Veterans Affairs Medical Center.
For chronic Lyme, Donta advocates longterm treatment – 6 months or more – with oral antibiotics such as tetracycline or an erythromycin-like drug that can kill bacteria inside cells.
“My advice is that if a patient starts to improve after two weeks, don’t stop. Keep going until he’s all better,” he says. Other specialists advocate longterm treatment with intravenous antibiotics, which may penetrate the nervous system better.
But all this is hotly debated. Steere, for instance, says, “Nowhere in the medical literature is there information to support the value of giving antibiotics for 10 months, and there is potential danger – such as allergic reactions, colitis or gall bladder problems.”
Rosalie Trevejo, a CDC veterinarian, agrees: “Treatment for over a year would be dangerous.”
Some answers may come from a $ 4.2 million study now getting under way at NEMC by Dr. Mark Klempner, who plans to follow 260 chronic Lyme disease patients, giving half of them 90 days of antibiotics and the other half a placebo.
Ideally, a vaccine could head off much of this misery, but that vaccine “fix” may not come as easily as once thought.
Two similar vaccines – one by Connaught Laboratories, Inc. and the other by SmithKline Beecham – have been tested in thousands of people and the results are now being analyzed, says Steere, the principal investigator of the SmithKline study.
But, he says, “There’s no vaccine ready for this season and I don’t yet know about next year.”
Others say the antigen, or marker, used in both these vaccines may not be the most effective one. A third company, MedImmune, Inc. is betting that a vaccine based on a different protein on the spirochete may work better, but it won’t even begin to be tested in people until next summer.
And some researchers worry that vaccines might reactivate infection in people who have had Lyme disease in the past. Donta has several recovered patients who were vaccinated and then “started to have symptoms after getting the vaccine, usually the booster. It makes you wonder whether the vaccine didn’t set something off.”
Other issues still simmer, too. Karen Vanderhoof-Forschner, who has had Lyme disease, believes her son caught it from her while she was pregnant. He died six years later.
But researchers are still unsure whether the Lyme spirochete can cross the placenta. So far, there’s some evidence in mice that it can, and three unconfirmed cases in people.
All of which means, says Vanderhoof-Forschner, that the best way to deal with Lyme disease is to prevent it.
Prevention is the key
Learn to look for the deer tick, Ixodes dammini, on your skin or clothing after walking in fields or woods. It looks like a dark speck about the size of the period at the end of this sentence.
- If you can’t avoid areas where ticks thrive – woods, marshy areas, high grass and bush – wear long pants tucked into high socks and long-sleeved shirts. Wearing light colors make it easier to spot ticks that get on your clothes.
- Insect repellants may also help. One called permethrin works, but you must apply this only to your clothing, not your skin. Standard repellants containing DEET (diethyltoluamide) are also effective and can be applied to the skin.
- Because too much DEET can cause nerve damage, adults should not use it at concentrations higher than 30 to 35 percent; children should not use concentrations higher than 10 to 15 percent. Never put DEET on infants under age 1.
- When you get home from a tick-infested area, shower or bathe and check yourself and your children carefully for ticks.
- Remove ticks with a pair of tweezers within 24 to 48 hours.
- If pets have been in tick-infested areas, check them, too, as well as areas where they sit or lie. Ticks can drop off from pets onto couches and rugs.
For more information:
If you are interested in enrolling in the New England Medical Center study of the treatment of chronic Lyme disease, call: 1-888-LYME-CTR. (1-888-5963-287)
- Lyme Disease Foundation hotline 1-800-886-LYME (1-800-886-5963)
- American Lyme Disease Foundation, Inc., 914-277-6970.